Pediatric Extraspinal Subcutaneous Sacrococcygeal Myxopapillary Ependymoma: Case Report and Minireview

Abstract

A 9-year-old girl presented with a slow-growing and painless mass for 7 months in the soft tissue of the sacrococcygeal region. Magnetic resonance imaging revealed a well-circumscribed solid mass located in the subcutaneous soft tissue of the sacrococcygeal area, but not affecting bone structures. The mass was completely removed, and the disorder was diagnosed as myxopapillary ependymoma. In addition, the MYCN gene amplification status of the tumor was evaluated. Extra-axial ependymomas are very rare tumors with a tendency to metastasis, but they are usually regarded as low-grade ependymomas. Long-time surveillance and follow-up are necessary even after complete excision. Besides, we also discuss the diagnosis of primary soft tissue myxopapillary ependymoma.

When a dermatopathologist encounters the ultra‐rare: A case series of superficial soft tissue/cutaneous myxopapillary ependymomas

“…Other reportedly negative markers are CD34, CD31, podoplanin, Μelan A, HMB45, SOX10, calretinin, ER, PR, CD30, AFP, SALL4, OCT3/4, synaptophysin, chromogranin, smooth muscle actin, desmin, myogenin, brachyury, H3K27M, p63, 3,8,20,25,29 and in the present study BRAF V600E and neurofilament protein. INI1 expression has been reported as retained in tumor cells 25,29 . Ki‐67 proliferation index is usually in the range of 2%–20%, 21,25,29,32 with higher values in tumors exhibiting anaplastic features, 20 and generally a greater propensity to metastasize 21 …”

“…Chromosomal copy number changes are frequent, including chromosome 7 polysomy, 35 gains of chromosomes 9, 16, and 18, and losses of chromosomes 22q, 10, and 13q 35 . Studies by fluorescent in situ hybridization have not shown amplification of EGFR 36 or MYCN genes 29 . MPEs' gene expression profile includes upregulation of HOXB13 , NEFL , and PDGFRA , also detectable at the protein level by immunohistochemistry.…”

“…19 Staining with mucicarmine is variable, while iron stains can highlight areas of hemosiderin deposition. 19 Immunohistochemical stains are important in confirming the diagnosis of MPE, as tumor cells consistently show strong and diffuse expression of GFAP, 8,25,[29][30][31] and variable expression of S100 protein. 8,29,31,32 EMA is usually negative, 8,25,29,32 but when expressed it can show a dot-like immunoreactivity pattern.…”

“…19 Immunohistochemical stains are important in confirming the diagnosis of MPE, as tumor cells consistently show strong and diffuse expression of GFAP, 8,25,[29][30][31] and variable expression of S100 protein. 8,29,31,32 EMA is usually negative, 8,25,29,32 but when expressed it can show a dot-like immunoreactivity pattern. 21 Other markers that have been reported to be expressed in MPEs are CD56 29,[31][32][33] and focal NSE and WT1.…”

“…8,29,31,32 EMA is usually negative, 8,25,29,32 but when expressed it can show a dot-like immunoreactivity pattern. 21 Other markers that have been reported to be expressed in MPEs are CD56 29,[31][32][33] and focal NSE and WT1. 25 Occasional tumors may show keratin expression, a pitfall in the differential diagnosis with metastatic carcinoma.…”